000
WTPZ41 KNHC 150238
TCDEP1
 
TROPICAL STORM PRISCILLA DISCUSSION NUMBER   4
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP162013
800 PM PDT MON OCT 14 2013
 
THE CLOUD PATTERN OF PRISCILLA HAS LOST SOME ORGANIZATION DURING THE
PAST SEVERAL HOURS. ALTHOUGH THERE HAS BEEN A NEW BURST OF DEEP
CONVECTION NEAR THE EXPOSED LOW-LEVEL CENTER...THE OVERALL
CONVECTIVE MASS HAS SHRUNK AND CLOUD TOP TEMPERATURES HAVE WARMED
SOME SINCE EARLIER TODAY.  THE INITIAL INTENSITY IS LOWERED TO 35
KT IN ACCORDANCE WITH THE LATEST DVORAK CI NUMBERS FROM TAFB AND
SAB.
 
THE INITIAL MOTION ESTIMATE IS DUE NORTH OR 360/07. THE CYCLONE HAS
BEEN MOVING NORTHWARD AROUND THE WESTERN PERIPHERY OF A MID-LEVEL
RIDGE OVER EASTERN MEXICO AND TOWARD A WEAKNESS TO THE WEST OF THE
BAJA CALIFORNIA PENINSULA. HOWEVER...A MID-LEVEL RIDGE IS FORECAST
TO BUILD TO THE NORTH OF PRISCILLA SOON...WHICH SHOULD CAUSE THE
CYCLONE TO TURN NORTHWESTWARD OR EVEN WEST-NORTHWESTWARD DURING
THE NEXT DAY OR TWO. IN 2 TO 3 DAYS...THE TRACK SHOULD BEND TOWARD
THE WEST ONCE THE SYSTEM DECOUPLES AND BECOMES EMBEDDED IN THE
LOW-LEVEL TRADE WINDS. THE NHC TRACK FORECAST IS SLIGHTLY LEFT AND
FASTER THAN THE PREVIOUS ONE...IN THE DIRECTION OF THE MULTI-MODEL
CONSENSUS TVCE.
 
MODERATE TO STRONG EASTERLY SHEAR AFFECTING THE CYCLONE IS FORECAST
BY THE GLOBAL MODELS TO DECREASE SUBSTANTIALLY IN ABOUT 12 HOURS
WHILE PRISCILLA MOVES OVER WARM BUT SLOWLY DECREASING SEA SURFACE
TEMPERATURES. DESPITE THE SOMEWHAT MORE FAVORABLE ENVIRONMENT
AHEAD...PRISCILLA IS ALREADY INGESTING MORE AND MORE OF A
STRATOCUMULUS FIELD INTO ITS CIRCULATION FROM THE NORTH. THIS
NEGATIVE FACTOR WOULD LIKELY PRECLUDE ANY SHORT-TERM
INTENSIFICATION. WEAKENING LIKELY IN ABOUT 48 HOURS DUE TO A
SUBSTANTIAL INCREASE IN WESTERLY SHEAR AND MUCH COOLER WATERS. THE
NHC INTENSITY FORECAST IS LOWERED RELATIVE TO THE PREVIOUS ONE AND
IS SLIGHTLY ABOVE THE BULK OF THE INTENSITY GUIDANCE. DISSIPATION
IS NOW SHOWN SOONER...BY 96 HOURS...IN AGREEMENT WITH THE GLOBAL
MODEL SOLUTIONS.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  15/0300Z 16.2N 115.8W   35 KT  40 MPH
 12H  15/1200Z 16.9N 116.5W   35 KT  40 MPH
 24H  16/0000Z 17.6N 117.7W   35 KT  40 MPH
 36H  16/1200Z 18.4N 119.0W   30 KT  35 MPH
 48H  17/0000Z 19.2N 120.2W   25 KT  30 MPH
 72H  18/0000Z 19.5N 122.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
 96H  19/0000Z...DISSIPATED
 
$$
FORECASTER KIMBERLAIN